The IEEE 802.11s specification (IEEE P802.11s™/D1.03, Draft STANDARD for Information Technology—Telecommunications and information exchange between systems—Local and metropolitan area networks—Specific requirements—Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications, Amendment <number>: ESS Mesh Networking) proposes an airtime metric which is concerned with minimizing the total medium usage and uses a current PHY rate to calculate the total time that a packet will be used over the air when going from a source to a destination. This metric is very simple in concept and some in the industry feel that it does not account adequately for battery powered devices, additional latency due to power save nodes, load balancing, and other issues.
In addition, mesh networks that are employed in connection with the IEEE 802.11s standard, and others, still continue to suffer from non-optimal properties that can be improved upon.